1. What percentage of people have a dog?

out of 300 people 129 persons said they own a dog or:

(129/300)*100 = 43% of the people have dog

2. How many (or what number of) people do not own a dog or a cat?

first lets find how many people own a cat

34% of 300 is: 0.34*300 = 102 people own a cat

102 + 129 = 231 people have dog or cat

the rest of the people: 300 - 231 = 69 people do not own a dog or a cat

3. What was the most popular pet among those surveyed? By how many responses does this pet lead?

the most popular pet is the one with the highest percentage and that is the dog with 43%.

129 people have dogs

102 have cats

300*0.17 = 51 have gerbil

the dog led with 129 - 102 = 27 responses before the cats.

the dog led with 129 - 51 = 78 responses before the gerbil.